The present invention relates to a method for maintaining solids in suspension in a liquid and to a container for use in the method. One example of application of the present invention lies in its potential use in slurry-fermentation processes in which organic or other slurries, such as animal or other wastes are caused, or allowed, to react to produce for example methane and a residue which may be used as a fertilizer and is better for spreading on fields than the original material.
It is known that the fermentation, or digestion, of organic wastes takes place under anaerobic conditions, being caused by anaerobic bacteria in the slurry, and the material must therefore be kept in closed containers for the duration of the fermentation period. This is a relatively long period, which may be of the order of several weeks, during which solids tend to come out of suspension if the slurry is not kept continuously agitated. This can cause various problems, not the least being difficulties in the removal of the solids if, for example, they compact at the bottom of the container or form a floating mass or crust.